iOS 12.1.2 (build 16C101) is an official Apple over-the-air update for the iPhone 6s, released on 2018-12-17T21:07:01Z. The update package is 300.85 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f5adf2088edd1d5cc8a6c46fdf0299b9cd273118.zip.